DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2015; Project Identifier MCAI-2023-00769-T]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Bombardier, Inc., Model BD-700-1A10 and BD-700-1A11
airplanes. This proposed AD was prompted by reports of missing or
damaged inboard flap seal plate assemblies. This proposed AD would
require repetitive inspections for cracks of the attaching angles of
the inboard flap seal plates and replacement. This proposed AD would
also require the eventual replacement of both inboard flap seal plates,
which would terminate the repetitive inspections. The FAA is proposing
this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by September
23, 2024.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2024-2015; or in person at Docket Operations between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket
contains this NPRM, the mandatory continuing airworthiness information
(MCAI), any comments received, and other information. The street
address for Docket Operations is listed above.
Material Incorporated by Reference:
For Bombardier material identified in this proposed AD,
contact Bombardier Business Aircraft Customer Response Center, 400
Cote-Vertu Road West, Dorval, Quebec H4S 1Y9, Canada;
telephone 514-855-2999; email ac.yul@aero.bombardier.com; website
bombardier.com.
You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 2200 South 216th St., Des
Moines, WA. For information on the availability of this material at the
FAA, call 206-231-3195.

FOR FURTHER INFORMATION CONTACT: Yaser Osman, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-
228-7300; email 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2024-2015; Project Identifier
MCAI-2023-00769-T'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
the proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Yaser
Osman, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; telephone 516-228-7300; email 9-avs-nyaco-cos@faa.gov. Any commentary that the FAA receives that is not
specifically designated as CBI will be placed in the public docket for
this rulemaking.

Background

Transport Canada, which is the aviation authority for Canada, has
issued Transport Canada AD CF-2023-42, dated June 19, 2023 (Transport
Canada AD CF-2023-42) (also referred to after this as the MCAI), to
correct an unsafe condition on certain Bombardier, Inc., Model BD-700-
1A10 and BD-700-1A11 airplanes. The MCAI states that there have been
multiple reports in service of missing or damaged inboard flap seal
plates. An investigation revealed a premature fatigue failure mode of
the inboard flap seal plates. Left uncorrected, an inboard flap seal
plate may partially or totally detach. Under certain flight conditions,
a missing inboard flap seal plate could lead to excessive buffeting and
vibration, and consequent damage to the airplane.
The FAA is proposing this AD to address the unsafe condition on
these products.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2024-2015.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Bombardier Service Bulletins 700-27-5509 and 700-
27-6509, both Revision 01, both dated May 5, 2023. This material
specifies procedures for repetitive detailed inspections for cracks of
the attaching angles of the inboard flap seal plates and replacing the
inboard flap seal plates if any crack is detected. This material also
specifies procedures for replacing both existing inboard flap seal
plates with structurally more robust redesigned components. The
replacement actions include a detailed visual inspection for damage
(including signs of failure, cracking, and deformation) of the flap
inboard closing ribs and trailing edges, an eddy current or liquid
penetrant inspection for cracks running out of the flap inboard closing
rib holes common to the outboard stiffener and angle, and repair for
cracks and other damage. The replacement would eliminate the need for
the repetitive detailed inspections. These documents are distinct since
they apply to different airplane models. This material is reasonably
available because the interested parties have access to it through
their normal course of business or by the means identified in the
ADDRESSES section.

FAA's Determination

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to the FAA's bilateral agreement with this State of Design Authority,
it has notified the FAA of the unsafe condition described in the MCAI
and material referenced above. The FAA is issuing this NPRM after
determining that the unsafe condition described previously is likely to
exist or develop on other products of the same type design.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified
in the material already described.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 43 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:

Estimated Costs for Required Actions

The FAA has received no definitive data on which to base the cost
estimates for the repairs specified in this proposed AD.
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this proposed AD may be covered under warranty, thereby reducing the
cost impact on affected operators.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.

Regulatory Findings

The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect on the States, on the relationship
between the national Government and the States, or on the distribution
of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive: